Door knob and method of making the same

ABSTRACT

A doorknob and method of making it concern a circular shell having a rim with an edge. Material of the rim is peeled by a relatively rotating tool and is distributed around the interior periphery of the rim to form an inwardly extending tongue having an interruption. An originally separate shank has a flange disposed within the peeled rim and shouldered against the tongue, being held permanently by the inturning of the rim edge. A tab on the shank is fitted into the interruption in the shell.

United States Patent Kenneth Raeburn Nelson West Vancouver, British Columbia;

Leslie William Pope, North Vancouver, British Columbia; Karl Greinacher, North Vancouver, British Columbia, all of, Canada Appl. No. 744,387

Filed July 12, 1968 Patented July 13, 1971 Assignee Schlage Lock Company Inventors DOOR KNOB AND METHOD OF MAKING THE SAME 80111115, 11 DrawingFigs.

U.S.C1 292/347, 29/161, 289/53 Int. Cl E0513 U06, 821d 53/38, F16d 1/06 Field of Search 292/347, 353, 350, 348; 29/161; 74/553; 339/95, 97 S;

References Cited UNITED STATES PATENTS 2/1940 Terrill 287/53 1,974,252 9/1934 Killorin 113/121 X 3,326,401 6/1967 De Longm. 215/38 407,817 7/1889 Case 292/347 447,266 2/1891 Wilmot 292/347 2,182,998 12/1939 Upton 339/97 2,873,988 2/1959 Bartholomew 287/126 FOREIGN PATENTS 16,699 1 1/1912 Denmark 3,004 2/1884 Great Britain 292/347 12,097 4/1903 Great Britain..... 292/353 161,069 4/1920 Great Britain 292/353 Primary Examiner-Marvin A. Champion Assistant ExaminerEdward J. McCarthy Attorney-Lothrop and West AESTRACT: A doorknob and method of making it concern a circular shell having a rim with an edge. Material of the rim is peeled by a relatively rotating tool and is distributed around the interior periphery of the rim to form an inwardly extending tongue having an interruption. An originally separate shank has a flange disposed within the peeled rim and shouldered against the tongue, being held permanently by the intuming of the rim edge. A tab on the shank is fitted into the interruption in the shell.

AIENTEH JUU 3 I971 SHEET 2 0F 2 FIG.

DOOR KNOB AND METHOD OF MAKING THE SAME In the fabrication of knobs, particularly hollow knobs, referred to herein as doorknobs and intended to include any actuating protuberance for use on a door, drawer, cabinet or the like, it is customary to make the hollow knob by any of several processes, usually involving the assembly of more than one piece of material. If metal is used, the pieces are often fitted together carefully and brazed and then finished. This is a relatively expensive and not always satisfactory arrangement. Alternatively, knobs are sometimes made by expanding a preformed shell hydraulically into a surrounding mold, This is a satisfactory process so far as operation and result are concerned, but it is expensive and is not well suited to limited production. All of the methods of providing hollow knobs known to us are involved with various disadvantages, usually cost or complexity or improper results.

It is therefore an object of this invention to provide a doorknob that is made of a number of pieces yet is held together satisfactorily in a workmanlike and economical fashion.

Another object of the invention is to provide a method for providing doorknobs that can readily be utilized in connection with limited production, with great economy and with satisfactory results.

Another object of the invention is to provide a doorknob comprised of a number of pieces without extraneous brazing or comparable, extra materials. a

A further object of the invention is to provide a doorknob that resists all of the strains put upon it even in extraordinary service and maintains its integrity.

A further object of the invention is to provide a process or method of making a doorknob in which the knob is made in several pieces which are readily assembled and held together permanently.

A further object of the invention is in general to provide an improved doorknob and an improved method of making the doorknob.

Other objects together with the foregoing are attained in the embodiments of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

FIG. 1, on the right half, is a side elevation of one form of doorknob constructed in accordance with the method of the invention and, on the left half, is a cross section on an axial plane through the knob;

FIG. 2 is a cross section on an axial plane of a preliminary part for use in the doorknob;

FIG. 3 is a side elevation of the part or shell of FIG. 2 with a portion broken away to show the interengagement of a forming or peeling tool with the shell;

Flg. 4 is a cross section on another axial plane showing the tool and shell in working relationship;

FIG. 5 is a cross section similar to FIG. 4 but showing the shell in an advanced stage of manufacture;

FIG. 6 is a view comparable to FIG. 5 but with the plane of section at right angles to the plane of FIG. 5;

FIG. 7 is a cross section, the plane of which is indicated by the line 7-7 of FIG. 5;

FIG. 8, on the left half, is a view of the knob in assembled and nearly finished condition, the' view being a cross section on an axial plane, and, on the right half, is an elevation of a finished knob;

FIG. 9 is a side elevation ofa different knob shell with a tool operating thereon, a portion of the shell being broken away on an axial plane to show the interior construction in cross sectron;

FIG. 10 is a cross section, thev plane of which is indicated by the line 10-10 of FIG. 9; and

In one of the forms of the invention, particularly as illustrated in FIGS. ll-8 inclusive, the process of providing the finished product is initiated with the provision of a metallic shell 6. The shell in the configuration shown may be the result of a several prior forming steps. The shell includes a rim 7 defining a margin of the body, the rim being circular cylindrical about an axis 8 so that the shell is a' figure of revolution. The rim 7 terminates in an edge 9 substantially perpendicular to the axis 8 and lying in a transverse plane. The rim 7 merges in a shoulder curve 11 with a domed top 12. The thickness of the wall included in the shell is substantially uniform throughout, as nearly as the various prefabricating processes will permit.

In accordance with the precess of the invention, the shell 6 is disposed to rotate relative to a tool 14 about the axis 8. So long as there is relative rotation it is immaterial whether the shell itself rotates with respect to the frame or base on which it may be mounted or whether the tool 14 so rotates. The tool 14 includes a mounting shank 16 having its longitudinal dimension not exactly parallel to the axis-8 but inclined with regard thereto at a small angle. THe shank 16 supports a cutting edge 17 adjacent a clearance and forming a groove 18 in an enlarged head 19 having a generally rounded surface 21 near the edge 17.

The tool and shell as they revolve relatively to each other likewise move axially toward each other. The cutting edge 17 enters the edge 9 of the shell and as the two revolve relatively partially severs and peels part of the metal of the rim and directs the cut and diverted material inwardly and away from the main thickness. In effect the rim of the shell is divided and one part of the rim material is reshaped. That is, the material which is partly separated by the cutting edge 17 or divided by the cutting edge 17 is not entirely removed, but rather is curled by the clearance groove 18 inwardly; that is, radially and axially inwardly, to afford a tongue 22 extending entirely around the interior of the shell. As the tool and the shell approach each other more and more, additional material is diverted from the shell into'the tongue, which finally extends inwardly in a curled fashion. The tongue has a relatively thick base and a relatively thin edge 23 somewhat irregular or serrated, although the general configuration of the tongue is predetermined and predictable. The rim 7 near the edge 9 after peeling has a tapered configuration in cross section due to the angular direction of travel of the tool. THe tapered section merges with the tongue to define a shoulder 24 or shelf. In this fashion the material of the shell is deformed or diverted to provide a somewhat thinner edge and also to provide a firm, circular shoulder or shelf.

The resulting work piece is still a figure of revolution about the axis 8, and since it is destined to operate by rotation it is preferred to provide some eccentric or noncircular portion thereof. Consequently, the partially completed body is next subjected to a cutting operation so that a discontinuity or notch 26 is provided in the tongue 22. At least one portion of the circular interior periphery of the tongue is interrupted. For symmetry it is usual to provide a second notch 27 opposite the first on a diameter in order to balance rotational forces on the knob.

The part as so far prepared is then coaxially assembled with a hollow shank 31. The shank is a preformed metal product having a circular cylindrical portion 32 and an outwardly extending platelike section 33 merging through a bead 34 with an upstanding flange 36. In addition, the shank has a pair of diametrically opposite tabs 37 and 38 serving as means interengaging with the notches or interruptions 26 and 27 in the shell. Not only are the eccentric portions 37 and 38 interfitted with the notches 26 and 27, but the axial assembly is continued until the flange 36 abuts or rests against the shoulder formed at the base of the tongue 22, the flange 36 lying within the inclined, interior surface of the rim 7. Following this as- FIG. 11 is a view comparable to the left half of FIG. 1 and showing the finished knob of this version in cross section on an axial plane.

sembly operation, the still-depending edge 9 is deformed inwardly to overlie and curve around the bead 34, thus locking the shank firmly in position with respect to the knob shell in a I concentric relation therewith and against axial movement in either direction, the relative rotation between the otherwise circular shell and shank being precluded by the extensions 37 and 38.

In this condition the knob is substantially finished except that in some instances it is preferred that the originally convex dome 12 and the originally cylindrical shell sides be of dif ferent contours. If so, the knob may be formed to invert the dome [2 to afford a concavity 41 as illustrated in the left half of FIG. I and so that the shell side takes on a convexity 42. Also, if desired, the shank can be provided with a pair of indented straps 43 and 44 serving as a key for the interengagemerit of the shank with the control part ofa lockset.

By this method there has been provided a doorknob of parts assembled in a completely fixed and rigid fashion against any dislodging forces. The material of the knob shell itself is deformed to provide a sturdy, accurately positioned shoulder against which the flange of the shank may be positioned, the contours precluding any relative rotation between the knob shell and the knob shank. In practice it has been found that a knob constructed in this way is relatively cheap even though production runs may be only moderate, and does not require the use of special labor, nor of any extraneous material such as brass for a brazing operation. The knob is readily assembled with customary locksets and can easily be finished to any finish required.

In some instances it is preferred to achieve a similar result without relative rotation between the initial shell and the forming or peeling tool. in that instance the arrangement of FIGS. 9-11 is followed.

An initial shell 51 has a generally circular cylindrical sidewall 52 ending in an edge 53. The shell is not rotated but is merely moved axially with respect to a forming or peeling tool 54 comparable to the tool 14. The tool and shell excursion is in the direction of the axis 56 in an approaching manner. The cutting edge 57 of the tool in entering the material of the shell edge peels the shell material and curls it to provide a tongue 58 affording a shoulder 59, as before. In this instance the tool 54 may move exactly in the direction of the axis 56 to provide a rim with parallel defining walls or may move at a slight inward or outward inclination in order to afford a taper on the lower portion of the sidewall adjacent the edge. I

The tool 54 makes a plurality of peeling cuts around the interior periphery of the shell, thus affording a number of tongues 58 separated by intervening spaces. The axial extent of each of the cuts is exactly the same, so that there is afforded a shoulder 59 around the interior periphery of the shell at the same axial location. Thus, it can be considered that there is a continuous tongue around the interior periphery of the shell except for interruptions between the individual peeled portions. If desired the tool 54 can be multiplied by the number of peeling cuts to be made and can be unified so that but a single stroke of the tool relative to the shell will suffice. In fact, that is the preferred commercial practice.

Within this shell there is inserted a shank 61 substantially identical with the shank previously described and having a flange 62 terminating in an edge 63 adapted to fit against the shell portions which have been peeled back and thus form a series of stops or shoulders. The flange of the shank is held against the shoulder 59 or plurality of shoulders because the edge 53 of the shell is formed over the bead 64 of the shank. As before, the shape of the finished knob can be given whatever contour is desired, particularly by deforming the dome to provide a concave surface 66. lfdesired, the sidewall 52 of the shell can itself be shaped to afford a convex portion 67. With this form of the invention as well, the process and product are superior to those previously produceable by other means and require no brazing or hydraulic expansion and lend themselves to moderate production with the knob and shank firmly secured together against all dislodging forces which might normally be encountered.

We claim:

1. A structural member for a doorknob comprising a circular shell having a continuous, approximately circular-cylindrical imperforate rim with an edge, and a plurality of integral tongue means projecting substantially radially from said imperforate continuous rim around a substantial part of the interior thereof to define a shoulder disposed within said shell with all of said tongue means at the same axial distance away from said edge.

2. A doorknob as in claim 1 in which said tongue means in a cross section in an axial plane have a tapered, curled shape.

3. A doorknob as in claim 1 in which said tongue means project toward the axis of said rim from a surrounding outer portion of said rim.

4. A doorknob as in claim 1 in which said rim has substantially a predetermined wall thickness throughout except that said predetermined thickness of said rim between said edge and said tongue means is divided between said tongue means and the remaining portion ofsaid wall.

5. A doorknob as in claim 1 in which said rim between said tongue and said edge is tapered in cross section in an axial plane and said tongue in said cross section is complementarily tapered.

6. A doorknob as in claim I including a shank having a flange disposed within said rim against said rim and said shoulder.

7. A doorknob as in claim 6 in which said shank has a bead and said rim is curled around said bead in a direction to hold said flange against said shoulder.

is. A doorknob as in claim 1 including a shank in part disposed within said rim, and means for securing said shank and said rim against rotation relative to each other including a tab on said shank disposed between said tongue. means. 

1. A structural member for a doorknob comprising a circular shell having a continuous, approximately circular-cylindrical imperforate rim with an edge, and a plurality of integral tongue means projecting substantially radially from said imperforate continuous rim around a substantial part of the interior thereof to define a shoulder disposed within said shell with all of said tongue means at the same axial distance away from said edge.
 2. A doorknob as in claim 1 in which said tongue means in a cross section in an axial plane have a tapered, curled shape.
 3. A doorknob as in claim 1 in which said tongue means project toward the axis of said rim from a surrounding outer portion of said rim.
 4. A doorknob as in claim 1 in which said rim has substantially a predetermined wall thickness throughout except that said predetermined thickness of said rim between said edge and said tongue means is divided between said tongue means and the remaining portion of said wall.
 5. A doorknob as in claim 1 in which said rim between said tongue and said edge is tapered in cross section in an axial plane and said tongue in said cross section is complementarily tapered.
 6. A doorknob as in claim 1 including a shank having a flange disposed within said rim against said rim and said shoulder.
 7. A doorknob as in claim 6 in which said shank has a bead and said rim is curled around said bead in a direction to hold said flange against said shoulder.
 8. A doorknob as in claim 1 including a shank in part disposed within said rim, and means for securing said shank and said rim against rotation relative to each other including a tab on said shank disposed between said tongue means. 